The invention relates generally to apparatus for feeding wood chips and the like into a treatment bin, and deals more particularly with such apparatus which maintains a seal with the bin to prevent gases from escaping.
In the course of manufacturing certain wood products, wood chips are fed into a bin where they are pre-steamed or otherwise treated with chemicals. At all times, it is important to prevent the steam and other gases within the bin from escaping, and the air outside from entering into the bin. Thus, the wood chips should be fed into the bin through a suitable seal.
For example, Kamyr Aktiebolag, a company located in Karlstad, Sweden, has manufactured and sold a feeder with a rotary pocket air lock to provide the seal, and a horizontal screw conveyor to feed the wood chips into the bin. Although this feeder is effective, it requires closely fitting parts to maintain the seal, and the parts are subject to wear and require maintenance.
Accordingly, a general object of the present invention is to provide a wood chip feeder which does not require closely fitting parts to make a seal, yet is effective in both feeding the wood chips and providing the seal.
Another general object of the present invention is to provide a wood chip feeder of the foregoing type which requires little maintenance.
A more specific object of the present invention is to provide wood chip feeders of the foregoing types which provide the seal even when wood chips are not fed into the bin.